1. Field of the Invention
The present invention relates to processed meat, meat products prepared using the same, and a method for the production of the processed meat and the meat products. The processed meat and the meat products prepared from the such processed meat by the production method have the meat tissues, such as the perimysium, myofibril, sarcolemma, collagen and lipids in the skeletal muscles of the flesh, fats, and the cell membranes and collagen in the fat tissues thereof, solubilized by a salt, thereby assisting the action of an alkali in gelling or emulsifying the meat tissues and as a result providing the processed meat with improved water retention capability or water-binding characteristics and cohesive or meat-binding properties. They are further provided with the properties of preventing meat juice (drip) from flowing out from the meat during freezing or thawing or upon cooking, preventing denaturation of the meat due to the softening or gelatinization of the flesh fibers and fats or due to the oxidation of the animal meat tissues. Furthermore, the processed meat and the meat products prepared from the same can improve meat quality and assist in retaining or improving a color of the meat closer to a clear color of fresh meat. The method according to the present invention can produce the processed meat and the meat products therefrom in more efficient way and in a shorter time than conventional methods.
2. Description of the Related Art
In recent years, flesh or meat of livestock animals, such as calves or oxen, horses, pigs, sheep, poultry, etc. and non-domesti cated animals, such as boar, deer, etc. have been commonly employed for meat food materials. The flesh of the animals is usually processed for meat as food and cut into meat joints which in turn are further cut into smaller meat portions appropriate for cooking. The meat may be cooked, e.g. grilled, roasted, fried, stewed, braised, boiled, or otherwise cooked, depending upon its portions, tenderness and other meat quality. The meat are generally stored for a long period of time by freezing, refrigerating, dry-freezing, canning, smoking or otherwise processing by traditional methods.
It is to be noted herein that the term "meat" referred to herein is intended to mean flesh or meat of animals including birds as well as mammalian animals, when it is apparent in the context of this specification or unless otherwise defined herein.
Generally, meats of animals are rapidly frozen or refrigerated immediately after slaughter and they are transported as frozen or refrigerated meats to processing plants or establishments. They are then processed and distributed in the market as processed meats and as processed meat products. As a matter of course, meats may undergo deterioration and lose meat quality during storage by freezing or refrigerating for a long period of time. Further, thawing such frozen or refrigerated meats may cause deteriorating in meat quality, too. In particular, conventional processes for thawing such frozen or refrigerated meats suffer from the disadvantages that savoring and nourishing components are caused to ooze out or flow out during thawing processes, together with meat juice, and therefore they may lose their original taste and flavor from the frozen meat, in accompany with the outflow of such meat juice upon thawing. They also cause the problems that low-molecular proteins and blood flown out from the frozen meat during thawing or freezing, together with the meat juice, are oxidized rapidly during thawing to cause deterioration in the meat quality of the meat and to spoil the color of the meat, thereby giving off an unpleasant smell. The thawing of the frozen or refrigerated meat may further cause the problem that the outflow of the meat juice from the thawing meat reduces water contents in the thawed meat, thereby making the meat tougher upon cooking and providing the cooked meat with a coarse texture and a poor taste and flavor upon eating. Although conventionally processed meats suffer from the various disadvantages and problems during freezing or refrigerating or during thawing or upon cooking as described above, the meats are processed so as to adapt their meat quality to match with a variety of processed meats and meat products to be produced therefrom.
Further, conventional methods for processing meat may cause the problems that the processed meat reduces a meat yield on account of sublimation of water from the meat during refrigerating or freezing or due to the fact that meat juice is caused to ooze out from frozen or refrigerated meat during freezing or refrigerating or during thawing. It is also the great loss of resources that nourishing low-molecular components containing savory materials, i.e. tasteful and flavor-bearing materials are caused to flow out from the frozen or refrigerated or chilled meat during thawing and they are disposed of without being utilized whatsoever. At meat processing plants or establishments, it is further required to dispose of a large amount of such liquid waste so that special equipment for exclusive use for such disposal purposes is required to be installed and the operation of such disposal equipment requires labor and expensive costs.
For instance, at meat shops or supermarkets, chilled or refrigerated meat or unfrozen meat is being sold while displayed in a showcase which is managed at low temperature so as to prevent the chilled or refrigerated meat from thawing or the meat from discoloring or deteriorating in its meat quality due to the oozing of meat juice or for other reasons during displaying. Once chilled or refrigerated meat is purchased by consumers, however, it may be thawed flowing out meat juice and deteriorating in meat quality and spoiling the meat color on the way back to home in many cases. Further, processed meat products, such as hamburgers, prepared by thawing chilled or refrigerated meat and freezing or refrigerating thereafter may present the problems that meat juice is caused to flow out from the meat materials used for meat products, in particular, during cooking by heating and that various fats and oils contained in the meat juice oozed from the meat products are caused to solidify into white and waxy solid materials upon cooling. Such waxy and white solid materials may provide a rough and unpleasant palate and spoil a favorable taste as meat.
In order to improve the problems and disadvantages inherent in the conventional methods and processes for processing meat of animals, there have been proposed a variety of methods and processes for processing.
For instance, Japanese Patent Laid-open Publication (Kokai) No. 54-80,456 proposes a method for the production of corned beef, which comprises cutting fasciae, tendons, etc. of meat bulk into smaller pieces, adding an additive, such as a phosphate or sodium nitrite, to the small meat pieces, stirring them under reduced pressure at 60 mmHg or higher and, as needed, soaking them in a solution at 3.degree. C. to 5.degree. C. for 48 hours, followed by boiling them at 115.degree. C. to 118.degree. C. for 60 to 90 minutes to loose or unfasten them by removing the fasciae, tendons and blood vessels from the processed meat. This method can achieve an improvement of yield in production by 15% to 25%. The method, however, suffers from the disadvantages that the steps are so complicated to require a long time for processing and that as a result, productivity is poor. Further, this method presents the drawbacks that the color of the resulting meat is unsuited for corned beef and that the processed meat is not very preferable in terms of safety as food because it contains the such additive.
Japanese Patent Laid-open Publication (Kokai) No. 59-39,111 discloses a method for the production of blocks of chicken, which comprises adding sodium chloride to chicken in bulk form at the rate of from 1% to 3% by weight with respect to the total weight of the meat and mixing the chicken bulk with stirring gently by means of an agitator and a mixer machine, without damaging inner tissues of the meat bulk, thereby allowing salt-soluble proteins to exude from the meat bulk onto the surfaces of the chicken meat in a meat paste form. The meat is then incorporated and filled into a mold at reduced pressure and heated to solidify yielding chicken blocks. Therefore, this method can provide chicken blocks having their meat surfaces enclosed with such meat paste. This method, however, has various shortcomings that the method involves a reaction on the meat surfaces only and that the meat quality inside the meat bulk cannot be modified. Further, as this method requires working steps which have to be carried out under reduced pressure and which consist of a molding step that lasts from 12 to 48 hours and a heating step that lasts from 2 to 3 hours, it may cause the problems that it is so complicated as a whole that costs of manufacturing may become expensive and productivity may be poor.
Further, Japanese Patent Laid-open No. 62-29,953 proposes a method for the production of pickle for preserving processed meat and of processed meat preserved in such pickle. In this method, the pickle heated with steam is injected into meat stock, followed by addition of a coloring agent or an edible pigment. Thus, it has been found that in this method the concentration of sodium chloride in the meat is so low that the sodium chloride can exert a very poor effect upon the meat and its action to gel or emulsify the meat is extremely mild, thereby failing to modify the quality in meat tissues to a sufficient extent. The processed meat prepared by this method contains a low concentration of salt and phosphoric acid and has a low calorific value, however, it is less resilient and it is poor in texture that gives a pleasant palate upon eating. Further, the meat processed by this method presents the problems that it is likely to be oxidized and its color is readily spoiled.
A method for the production of seasoned meat, as disclosed in Japanese Patent Laid-open Publication No. 3-180,138, comprises soaking meat in a large amount of pickle containing appropriate amounts of finely divided salt, a saccharide, a coagulant, a coloring aid, an emulsion stabilizer, a pH adjusting agent, and so on for 10 to 30 hours, the pickle being adjusted so as to have a concentration near that of the body liquid. This method, however, suffers from the disadvantages that the pickle cannot penetrate through and into the inside of meat blocks when the meat blocks in large bulk form are soaked in the pickle, the quality in meat may vary widely from one meat block to another, and the color of the meat may be spoiled readily. Further, this method has the problems that it is difficult to modify the fat layer of the meat and it lacks a high productivity.
Furthermore, Japanese Patent Laid-open Publication No. 58-37,826 discloses a method for the production of processed meat, in which sodium chloride is added to a lump of meat so as to adjust the ion intensity on the meat surface to 0.6 or higher, thereby exuding actomyosin onto the meat bulk surface, and then the meat is refrigerated at -2.degree. C. to -8.degree. C., followed by applying a pressure of 3 to 70 kg per square centimeter to the meat bulk. This method involves exuding actomyosin onto the meat surface and allowing the meat in bulk form to attach to each other through the actomyosin. If there is a fat layer in the meat bulk, no or little actomyosin can be exuded from the meat bulk. Even if the meat bulk could be attached to each other, it may be readily broken down into small pieces during cooking by heating. Therefore, this method suffers from the disadvantages that small pieces of meat cannot be utilized effectively as a whole, it lacks a high degree of workability and its productivity may become poor.
In addition, Japanese Patent Laid-open Publication No. 2-308,774 proposes a method for reforming meat in small bulk form, which comprises preparing meat for paste by adding a part by weight of an agent for dissolving myofibril protein to from 10 to 90 parts by weight of meat bulk so as to adjust pH to pH 6.0 to pH 7.3, and kneading the resulting meat for paste with 10 to 90 parts by weight of another bulk of meat adjusted to pH 6.5 or lower with a vacuum agitator, a line mill or a line mixer by avoiding incorporation of oxygen gas. This method, however, has the problems that an agent is required as an aid for attaching the meat in bulk form to each other because the meat cannot be attached to each other or the force by which to attach the meat bulk to each other is very weak through actomyosin that cannot be or is little exuded from the meat bulk if fat layers are located in the meat bulk. In addition, this method is difficult to increase productivity due to its complicated steps for processing.
For instance, U.S. Pat. No. 3,556,807 incorporated as reference in European Patent Publication No. 0 209 268 A2 discloses a process for tenderizing meat by soaking the meat in a solution of sodium bicarbonate. It is also known that, for example, European Patent Publication 0 028 113 incorporated as reference in European Patent Publication No. 0 209 268 A2 discloses the method of treating meat with phosphates in conjunction with sodium bicarbonate. It is found, however, that the use of sodium bicarbonate singly or in conjunction with phosphates cannot achieve the effects sought to be attained by the present invention. Further, it has the problem that it may impair the taste of the meat and deteriorate the quality in the meat to a great extent.
In addition, European Patent Publication No. 0 209 268 A2 discloses a process for treating meat with at least one alkali metal chloride and at least one additive selected from alkali metal bicarbonates, alkali metal carbonates, and alkali metal sesquicarbonates, for example with a solution of alkali metal chloride and such additive. This prior art publication discloses to the effect that the such alkali metal chlorides may include, for example, sodium chloride and the such alkali metal bicarbonates may include, for example, sodium bicarbonate and so on. Particularly noted is that the prior art publication uses the additives such as sodium bicarbonates in a mole concentration lower than that of the alkali to be used for the present invention particularly when the meat is processed in substantially the same manner.
Moreover, European Patent Publication No. 0 209 268 A2 discloses to the effect that the process of treating the meat may be effected, for example, by soaking the meat with the solution or by injecting the solution into the meat, or by a combination of soaking and injecting.
It is to be noted herein that the prior patent publication does not clearly teach or even imply the processing of the meat by applying external force to the meat in order to achieve the results to be expected to be attained by soaking or injecting the meat or other means, as disclosed in the prior art.
This process can bring about a reasonable enhancement in the meat-binding and water-binding properties of the meat by contacting the meat with the solution containing sodium chloride and the above-mentioned additives. The such reasonable enhancement brought about by contacting the meat with the such solution is not sufficient enough to achieve the ability of gelling meat.
Given the foregoing technical background for processing meat of animals, extensive studies have been made with the attempt to solve the problems and drawbacks inherent in the conventional and prior art methods and processes for processing the meat. As a result, it has been found that the use of a salt in combination with an additive at a particular rate can sufficiently achieve the objects of this invention as will be set forth in the description that follows.
As a result of extensive studies so far conducted, it is further found that the salt and the alkali can be impregnated in the meat in a very shorter period of time than as disclosed in the prior art and as by conventional methods.